In a communications system, flow control regulates the flow of communications traffic from one stage of the communications system to another stage. This other, or second, stage may not always, or even ever, be able to accept such traffic from the first stage at the maximum possible discharge rate by the first stage towards the second stage. The flow control mechanism Xensures that a source of a dataflow does not overwhelm a destination, which could occur by the source transmitting data to the destination at a rate exceeding that which the destination can process. If the destination were to be overwhelmed in such fashion, data would be lost, and additional network bandwidth would be consumed for any necessary retransmissions. Satellite communication systems face the added challenge of delay stemming from signal propagation over great distances. Thus, retransmission is extremely costly.
Modern satellite communication systems provide a pervasive and reliable infrastructure to distribute voice, data, and video signals for global exchange and broadcast of information. These satellite communication systems have emerged as a viable option to terrestrial communication systems for carrying data traffic (e.g., Internet traffic) as well as telephony traffic. However, because of spectral limitations, satellite communication systems are bandwidth constrained relative to terrestrial networks. In addition, modern data applications, which can include multimedia and real-time applications, often demand high-speed transfer of large amounts of data, such that a satellite communication system would likely be unable to service such great demands all at once. Accordingly, flow control is particularly critical between end hosts that utilize a satellite communication system as the transport network.
Traditionally, service providers have generally relied on end systems or hosts to implement flow control, without intervention by intermediate networks (e.g., transport network of the service provider). This lack of involvement is even more prevalent when the transport network is a satellite network, which traditionally acts simply as a relay.
Based on the foregoing, there is a clear need for improved approaches for flow control over a system that is bandwidth constrained and encumbered by delays.